Chapter: 14

What Are Statistics ?

Statistics is a branch of study that deals with the collection, presentation, analysis and interpretation of data.


Facts or figures, collected with a definite purpose.

Graphical Representation Of Data

Bar Graphs, Histograms of uniform & varying widths and frequency polygons.

Raw Data

The data obtained in original form.

Grouped Data

The data given in the form of class interval such as 0โ€“20, 20 โ€“ 40, and so on.

Class Size

Upper limit - Lower limit


The number of times an observation or group observations occur.

Exclusive Form

Upper limit of the one class is lower limit of the next class.

Inclusive Form

Upper limit of the class is not same as lower limit of the next class.

Class Mark

(Lower limit+Upper limit/2)